@mixin flex($direc, $just, $align) {
    display: flex;
    flex-direction: $direc;
    justify-content: $just;
    align-items: $align;
}
header, footer, main {
    width: 100%;
}
header {
    @include flex(row, center, center);
    height: 90px;
    background: #333333;
}
// main {
//     height: 100%;
// }
main {
    .main {
        min-width: 1200px;
        background: #fff;
    }
}
footer {
    a{ 
        display: block;
        color: #999 !important;
        text-decoration: none;
      }
    a:hover {
        color: #31A557;
    }
    ul li{
        list-style: none;
    }
    h3{
        color: #999;
        font-size: 18px!important;
    }
    .footer-copyright{
        color: #999;
    }
      
}
